1. Field of the Invention
The present invention relates generally to an electronic apparatus such as an electronic still camera and, more particularly, to an apparatus arranged to record a photographed image on, for example, a recording medium which is rotating.
2. Description of the Related Art
It has previously been proposed to provide a so-called electronic still camera, that is, a still camera of the type arranged to form a still image on its solid-state image sensor such as a charge-coupled device (CCD) through a photographic operation and record the still image on a recording medium such as a magnetic disk. An arrangement in which a still image recorded on the magnetic disk is reproduced and displayed on a monitor or printed on paper by means of a printer is also known in the art.
As compared to a still camera of the conventional type employing a silver-salt photographic film, such as an electronic still camera, has the advantages of requiring no chemical treatment such as development, permitting a photographed image to be immediately viewed on a monitor or in the form of a hardcopy, and permitting a photographed image to be transmitted to a remote location.
However, the electronic still camera has a number of disadvantages. For example, a large amount of electrical power is consumed during the rotation of the magnetic disk for use as a recording medium or the driving of the image sensor. If an electrically-operated focal-length adjustment mechanism for adjusting the focal length of a photographic optical system is incorporated in the camera, an additional amount of electrical power will be consumed for a focal-length adjustment operation, and the source battery of the camera will be consumed within a short period.
If recording on or reproduction from the magnetic disk and adjustment of the focal length are simultaneously performed with the source battery consumed to some extent, the voltage of the source battery may temporarily become lower, with the result that variations may occur in the rotation of the magnetic disk, introducing a distortion into a recorded or reproduced image. This is a vital defect.
In addition, if the driving of the image sensor and the above-described focal-length adjustment operation are simultaneously performed, a problem will be encountered in which the image signal output from the image sensor undergoes a disturbance due to a decrease in the source voltage.
In a case where a single camera includes a plurality of circuits each consuming a large amount of electrical power when in operation, it is theoretically desirable to employ a battery having a fully large capacity. However, in practice, battery capacity and a space for housing the battery are limited.